The present invention relates to a method of determination of the penetration depth of a processing tool, as well as to a device for performing the method.
In aviation more and more frequently carbon fiber plates are used, for example for manufacture of fuselages, stabilizer shells and the like, for weight reasons. They are fixed with one another by glueing and additionally almost always connected by rivets for safety reasons. Depending on the dimension of an airplane, several thousands rivets can be required, in particular for connection of the shell-shaped outer coating parts of an airplane with one another. These very high quantities of the required rivets play a not insignificant role in the total weight. Because of this reason, it is recommended to select the rivet shaft lengths of the rivet, as required for the pressing and transverse forces, with consideration of the thickness of the plates to be connected with one another. When aluminum plates are used as the materials, the total material thickness can be determined summarily since the aluminum plates do not have significant tolerances in their thicknesses. Carbon fiber plates to the contrary are known to have very high tolerances with respect to their thickness. The exact borehole depth of a material composite, composed for example of carbon fiber plates which are fixed with one another by glueing, can not be summarily determined since the drilling depth depends significantly on how thick the adhesive medium was applied between the parts to be connected and what is the residual thickness of the adhesive medium after its hardening. This means that the depth of each opening must be measured separately and a rivet with a corresponding shaft length must be associated with a respective opening, to satisfy the high requirements of the smallest possible weight.